Function to extract data from images to numpy array. If the dataset images havn't got the same shape it will be resized. This numpy array will have the shape (num_samples, width, height, channels). The numpy array data will be stored to npy files for later on, fast read-in data. The dataset has to be stored one class per sub-folder in the given file_dir. The values are in [0, 255] ant the targets are the class nums.

• NumPy
• OpenCV-Python
• Matplotlib